The following abbreviations are herewith defined, at least some of which are referred to in the following description associated with the prior art and the present invention.    AN Access Node    CC Continuity Check    Co Central Office    DSLAM Digital Subscriber Line Access Multiplexer    FDB Forwarding Database    GDA Group Destination Address    IP Internet Protocol    IPTV Internet Protocol Television    IO Intermediate Office    MAC Media Access Control    MEP Maintenance End Point    MIP Maintenance Intermediate Point    RGW Residential Gateway    SAI Service Area Interface    SHE Super Headend    STB Set-Top Box    TV Television    TLV Type Length Value    VHO Video Hub Office    VLAN Virtual Local Area Network
An in-band diagnostic tool is needed that can be used to retrieve user subscription data from the nodes on a path between a given source node (source MEP) and a given destination node (destination MEP) within a layer 2 aggregation network. Today, out-of-band diagnostic tools exist which can retrieve user subscription data but these out-of-band diagnostic tools require a common network management system which functions across different types of product platforms to retrieve user subscription data from the nodes on the path between the source MEP and the destination MEP within the layer 2 aggregation network. The out-of-band diagnostic tools can be difficult to implement because they use a common network management system which needs to function across different types of product platforms. Thus, the need for an in-band diagnostic tool which can retrieve user subscription data without requiring the tedious procedures associated with using the traditional out-of-band diagnostic tools. This need and other needs are satisfied by the present invention.